Airworthiness Directives; Boeing Model 737-100, -200, and -200C Series Airplanes

This amendment adopts a new airworthiness directive (AD); applicable to certain Boeing Model 737-100, -200, and -200C series airplanes; that requires repetitive inspections of certain floor beams and transverse beams, and corrective actions, if necessary. For certain airplanes, this AD also provides optional terminating action for the repetitive inspections. The actions specified by this AD are intended to detect and correct cracking at the aileron control quadrant cutouts and in the cabin floor beams and pressure web transverse beams above the main wheel well, which could result in rapid loss of cabin pressure and reduced structural integrity of the airframe.